This proposal is for the acquisition of a new transmission electron microscope and digital camera for use in NIH funded research and training, and other research, as well as undergraduate education. NIH-funded research on identification of proteins and characterization of molecular mechanisms involved in organizing microtubule minus ends at spindle poles in mammalian cells, interaction of Staphylococcus aureus with mammalian cells, and human colonization by the bacterium Vibrio cholera , all depend on high quality transmission electron microscopy for examination and evaluation of experiments. The transmission electron microscope (ThM) chosen is a JEOL USA, Inc. JEM-lOlO TEM, a 100KV microscope with 0.2 nm resolution, high tilt (+ or -60 degrees) pole piece, while the camera is a Gatan, Inc. Model 792 BioScan 1K by 1K wide angle CCD camera. The microscope and camera will be housed in the Rippel Electron Microscope Facility (REMF), an institutional resource, where it will be covered by service contract and a full time staff for training, research assistance and maintenance. The existing Faculty Advisory Committee will be extended to include the PIs for the purpose of ensuring access to the TEM. The TEM? to be replaced is 24 years old and has an anticipated life of no more than two years, despite having been continuously under service contract. The research of the principle investigators cannot be completed without continued availability of a transmission electron microscope.